A linear guide device comprises a rail, at least a slide member and multiple rows of rolling elements. The rail has multiple of axially extended raceways on its outer surface. The slide member is at least composed of a rigid body, a front and a rear end cap. The rigid body has a flat plate portion and two leg portions; on their inward surface there are multiple rows of raceways corresponding to the raceways on the rail one-to-one. The slide member further provides return channels aligning beside each raceway and turnaround channels for connecting the raceway and the return channel at the front and the rear end; whereby recirculation passages for the rolling elements are formed. The out wall of the turnaround channels is formed by the front and rear end caps. The slide member rides on the rail, having its unlimited sliding movement facilitated by the rolling elements rolling between the raceways of the rail and the slide member and circulating in the recirculation passage.
To prevent the wear of the rolling elements while rolling on the raceway, a permanent and sufficient lubrication on the contact surface between the rolling element and the raceway is required, there has been known a linear guide device as disclosed by U.S. Pat. No. 6,155,717, linear movement device and lubricant supplying device used therefor. Such a lubricant supplying member, mounted on the front side or the rear side of a slide member, comprises a lubricant coater brought into contact with the rail for coating the lubricant on the rail, a lubricant absorber installed contiguous to the lubricant coater for supplying the lubricant to the lubricant coater while absorbing the lubricant and holding the lubricant and lubricant amount controlling means for controlling an amount of the lubricant supplied from the lubricant absorber to the lubricant coater. However, according to this lubricant supplying system the lubricant supplying member applies lubricant to the rail outside the slide member, the slide member has to go over a distance longer than its length so that all the rolling elements can be lubricated. Therefore, the stroke of the slide member cannot be too short one side and the slide member becomes therefore longer than as normal the other side.
The lubricant supplying member may have a passage for further connection to another lubricant reservoir or an external lubricant reservoir through an lubricant inlet to enhance the lubricant reserving capability. To achieve the automatic lubricant supply ability the capillary phenomenon is applied to transport the lubricant, using materials like fibers, polymers, fur, . . . etc. The publication U.S. Pat. No. 6,125,968, lubricating oil supply system for a rolling guide apparatus, has disclosed an lubricant supply system, which comprises a supply member having a casing and a lubricating oil holding element impregnating the lubricating oil, fixed to the slide member and applying the lubricating oil with respect to the rolling surface of the rolling element or the rail together with a motion of the slide member, a reservoir tank including an element for occluding the lubricating oil disposed within the reservoir tank and mounted to the movable element, and a supply tube having a fiber entangling element therewithin and introducing the lubricating oil within the reservoir tank to the supply member, said fiber entangling element being in direct contact with both the lubricating oil holding element and the element for occluding the lubricating oil and thereby conducting the lubricating oil between the reservoir tank and the supply member. However, according to the lubricating oil supply system, when the tube is relative long and the hole is small, the entangled fiber is hard to be filled into the tube; also when the supply member, locating inside the slide member, has an anfractuous channel for connecting the lubricant tank; the entangled fiber is also hard to be filled into the channel.
On the other hand, the end caps providing the outer wall of the turnaround channels are normally made of injection-formed plastic objects and fixed by screws on both end surfaces of the rigid body of the slide member. The end cap has a hollow shape largish than the cross-section shape of the rail for the pass-through of the rail. The outer wall of the turnaround channels is thereby cut by the hollow shape and become thinner in the connection region between the raceway and the turnaround channel; the outer walls of said connection region becomes the weakest place. Limited by the space of the linear guide, the lowest recirculation channel always locates near the bottom of the slider member. The locations of the screws for fixing the end cap on the rigid body can only away from said connecting region between the raceway and the turnaround channels and beyond the lowest recirculation channel. The moving speed of the slide member on the rail increases, the direction-change impact from the rolling elements received by the turnaround channel increases too. A bending stress is generated between the impact acting point and the screw-fixing point; such bending stress facilitates the damage of the outer wall of the turnaround channel. Said connection region and the bottom side of the end cap are thereby facilitated to open and away from their position; such will cause an unsmooth recirculation of the rolling elements. Conventional seal plate design mounted on the outside of the end cap is fixed on the end cap only and can not improve the strength of the connection between the end cap and the rigid body.